In the conventional technology, the bidirectional resonant DC-DC conversion circuit generally has a topology structure of two-level direct current input/output on one side and two-level DC output/input on the other side. Therefore, mutual conversion between the single direct current bus and dual direct current bus cannot be achieved by using the topology structure. For example, the topology structure cannot be applied in a scenario where a two-line battery is connected to a three-level UPS.
Therefore, it is desired to provide a new bidirectional resonant DC-DC conversion circuit to solve the above problems.